1. Field of the Invention
The present invention relates to a structure of a container having a barrier material layer such as a fuel tank mounted on a vehicle.
2. Description of the Related Art
Recently, in a fuel tank mounted on a vehicle prevails resin-made one by blow molding from a viewpoint of such a rust resistance and weight saving. In most cases, in order to suppress a permeation (permeation of an HC (Hydrocarbon) mainly contained in fuel) of fuel such as gasoline reserved inside, the resin fuel tank has a barrier material layer of which a wall portion consists of such an EVOH (Ethylene Vinyl alcohol copolymer), and in general, is often composed of the wall portion of a multilayer section structure having the barrier material layer and thermoplastic resin layers consisting of such PE (Polyethylene) formed inside and outside, sandwiching the barrier material layer. For example, in Japanese Patent Laid-Open Publication No. 2005-82013 is described a fuel tank of a multilayer section structure having an HC barrier material layer and a hot-plate-welding layer as a thermoplastic resin layer formed with sandwiching the HC barrier material layer.
As a conventional technology for fixing a resin fuel tank is cited a method of hanging a band across a lower surface of the tank and applying a load to its whole vehicle body in a case of fixing the tank on a floor lower surface under a vehicle cabin. However, because the band member is separately required, the method connects to a problem that a number of parts and a weight increase; moreover, an arrangement space of the band member must be ensured as a space around the tank.
On the contrary, if adopting a structure of integrally forming a flange at an outer face side of a fuel tank in a pinch-off portion of a blow molding mold and drilling a bolt fixing hole in the flange, a fixation member such as a band member is not required, the tank can be fixed on its vehicle body only with a bolt through the flange, and the problem is expected to be eliminated. However, in the structure an inner peripheral face of the bolt fixing hole penetrating the flange results in being exposed outside, that is, a part of a thermoplastic resin layer formed between barrier material layers results in being exposed, and there is a problem that permeable fuel leaks outside from the exposed thermoplastic resin layer.
The present invention is performed to solve such the problem, and in a structure of forming a flange in a container such as a fuel tank in a pinch-off portion of a blow molding mold and drilling a bolt fixing hole at the flange, the invention intends to provide a structure of the container of being able to reduce a discharge amount of permeable fuel from the hole by simple configuration